This invention relates to the field of display systems, more particularly to sequential color display systems.
Image display systems create images by emitting, or modulating, light. The light forms an array of picture elements, or pixels, which together form an image. Full-color images are formed by creating three independent single-color images. Simultaneous color systems, such a cathode ray tube (CRT) based display systems, use three electron guns simultaneously to stimulate three color-generating phosphor regions for each pixel on the CRT screen. Sequential color systems typically use either three single-color light sources that are sequentially enabled, or a white-light source in combination with a sequential filter such as a color wheel.
Display systems are judged by many metrics, including horizontal and vertical resolution, brightness, color purity, display size, frame rate, and immunity from device created image artifacts, by which display systems are judged. Some of these characteristics are more important to consumers, either because they create a noticeably superior image, or simply because they differentiate between the systems on display in a store.
Brightness, or image intensity, is one metric that is extremely important to purchasers of display systems. Consumers"" preference for bright images places particular burden on the designers of color wheel based sequential color systems since only one-third of the light from the white light source is used at any given time. This inefficiency requires the use of a larger light source and more power compared to simultaneous color systems that rely on beam splitters. Therefore, methods and systems to increase the image brightness of sequential color systems are needed in the art.
Objects and advantages will be obvious, and will in part appear hereinafter and will be accomplished by the present invention which provides a display system and method for achieving a brightness gain using a white segment with hue and gain correction. One embodiment of the claimed invention provides a method of converting image data from a three-primary color system to a three-primary and one-combined color system. The method comprising: providing three-color image data for a pixel, assigning a value dependent on a smallest of the primary color intensity input words to a combined color intensity word, and scaling the primary color intensity input words to create primary color intensity output words.
Another embodiment provides a method of converting image data from a three primary color system to a three primary and one combined color system. This method comprises the steps of providing three-color image data for a pixel, assigning a value dependent on a smallest of the primary color intensity input words to a combined color intensity word, and assigning a value to each of three primary color intensity output words, each said assigned value equal to the sum of the corresponding primary color intensity input word and a hue correction value.
Another embodiment provides a method of converting image data from a three primary color system to a three primary and one combined color system. This method comprises the steps of providing three-color image data for a pixel, assigning a white component intensity value as a function of a minimum of the primary color input intensity words, determining a saturation value for the pixel, calculating a gain level based on the saturation level, adjusting the gain level based on a maximum of the three primary color input intensity words, and scaling each of the primary color input intensity words by the adjusted gain level to achieve an output intensity word for each of the three primary colors.
A display system comprising: an image data processing circuit and an image forming device. The image data processing circuit for receiving an input signal representing three primary color intensity words and generating a four color output signal comprised of an intensity data word for each of three primary colors and a combined color. The image data processing circuit further comprising a combined color intensity data generating circuit for generating an intensity word for the combined color, a gain correction circuit for adjusting the primary color intensity data based on a saturation level of the intensity data, and a hue correction circuit for adjusting the primary color intensity data to compensate for the addition of the combined color intensity data.